Materials such as polyurethane and leather can be wrapped around a stiffening shell to provide a stable shape and/or rigidity to a device case. The stiffening shell can be utilized to reinforce various portions of the device case. Unfortunately, in some cases the stiffening shell may not be robust enough to reinforce particularly fragile portions of the device case. For example, openings in the device case can be positioned particularly close to an edge of the casing. In such a configuration, a portion of the case defining the opening and bordering the edge can be particularly thin, creating what can sometimes be referred to as a thin web condition, thereby leaving the opening susceptible to damage or even breakage. Simply thickening the stiffening layer enough to achieve a robust opening can leave the device case thicker and/or taller than desired. Furthermore, moving the opening away from the edge can be unpractical as the position proximate the edge may be necessary to facilitate access to a portion of a device such as a user interface element along the lines of a button or switch.